Neuroscientific research shows that female brains and male brains have differences in terms of grey and white matter, corpus callosum size, hormone levels and the complexity of neural connections between the two hemispheres. Although the case does not present a problem on its own, the subject becomes problematic for the feminist philosophy of mind as the neural data is used in a sexist way to justify certain behavioural differences between women and men. Neuro-sexist view assumes that brain is hard-wired, therefore it is not capable of change. It is also claimed by many psychologists and philosophers that high amounts of testosterone cause significant changes in behaviour. Therefore, many gender normative arguments are believed to be justified as they depend on scientific information. In my thesis, I argue against this view suggesting that there might be some neurological and hormonal differences between a female’s brain and a male’s brain, but these differences are not the reason why there are psychological and behavioural differences between the two sexes. I claim that if there are any behavioural differences, they are mostly caused by psychological manipulation and social environment in which the individuals are brought up. I will challenge the neuro-sexist theories by making a close metaanalysis of the researches and the data, and then I will support the argument by bringing up some theories from the philosophy of mind. Lastly, I will investigate the moral side of this problem adopting a view from feminist ethics.